Ad hoc networking is a new paradigm of wireless commu- nications for mobile nodes. Mobile ad hoc networks work properly only if the partecipating nodes cooperate to network protocols. Cooperative algorithms make the system vulnerable to user misbehavior as well as to malicious and sel sh misbehavior. Nodes act sel shly to save battery power, by not cooperating to routing-forwarding functions. Lack of co- operation may severely degrade the performance of the ad hoc system. This paper presents a new approach to cope with cooperation misbehav- ior, focusing on the forwarding function.We present a general framework, based on reliability indices taking into account not only sel sh/malicious misbehavior, but also situations of congestion and jammed links. We aim at avoiding unreliable routes and enforcing cooperation, thus increasing network performability" (performance and reliability).